Wireless communications is a rapidly growing segment of the communications industry, with the potential to provide high-speed high-quality information exchange between portable devices located anywhere in the world. Potential applications enabled by this technology include, but are not limited to, multimedia Internet-enabled cell phones, smart homes and appliances, automated highway systems, video teleconferencing and distance learning, and autonomous sensor networks, to name just a few. However, supporting these applications using wireless techniques poses a significant technical challenge.
Presently, mobile phones employing the Global System for Mobile Communication (“GSM”) standard operate in multiple frequency bands. Mobile phones may be capable of three or four frequency bands, thereby allowing the mobile phone to be used with a variety of service providers. However, the speed and quality of GSM will not meet the requirements of the large data transmission of the future.
GPRS (General Packet Radio Services) is a packet-based wireless that promises data rates from 56 up to 114 Kbps and continuous connection to the Internet for mobile phone and computer users. GPRS is based on “regular” GSM (with the same modulation) and will complement existing services such circuit-switched cellular phone connections such as SMS or cell broadcast. Voice over IP over GPRS has also been explored.
Similarly, Enhanced Data rate for Global Evolution (EDGE) is a radio based high-speed mobile data standard. It allows data transmission speeds of 384 kbps to be achieved when all eight timeslots are used. This means a maximum bit rate of 48 kbps per timeslot. Even higher speeds and bandwidths are now available as WCDMA (Wideband Code Division Multiple Access) is implemented.
As handsets move to meet increased bandwidth needs, the requirements of components are more astringent. Battery life has to be maximized, reception clarity in a multitude of environments has to be improved and at the same time the customers require a significant reduction in size. These requirements burden the Radio Frequency (RF) front end modules (FEM) to be capable of modulating efficiently and dynamically between the leading global wireless broadband standards in a single platform solution.